Polycystic ovary syndrome (PCOS), characterized by chronic anovulation, hyperandrogenism, and insulin resistance, is estimated to affect four percent to eight percent of all women. In 1992, the investigators initiated the first large-scale study of cardiovascular risk factors in women with PCOS (1992-1994). They recruited 244 women with PCOS and 244 age-, race- and neighborhood-matched controls age (19-50 years of age) and determined that PCOS cases had a profile that conferred increased cardiovascular risk (increased LDLc, triglycerides, and waist/hip ratio, obesity, decreased HDLc, hyperinsulinemia, and increased diastolic and systolic blood pressure). During phase II, (1996-99) they investigated the prevalence of subclinical atherosclerosis (SCA) of the carotid arteries in women 30+ years of age from the original cohort. In preliminary analyses, PCOS cases 45+ years had significantly higher mean intima-media wall thickness (IMT) than controls (0.75mm vs. 0.70mm, p<.02). The investigators state that this well established cohort provides a unique opportunity to extend their study of CHD risk in women with PCOS by conducting more powerful longitudinal studies of SCA. The specific aims of the present study are to 1) recruit and screen 160 PCOS cases and 160 controls >=40 years from the original cohort to determine if PCOS cases have greater initial coronary or aortic calcification and/or greater progression during years 4 and 5, 2) evaluate the progression of carotid atherosclerosis over a 5-year period of PCOS cases and controls >=40 years who participated in Phase II of the study, 3) evaluate whether CHD risk factors can be linked to the extent of coronary and aortic calcification within cases and controls, 4) evaluate vascular stiffness in PCOS cases and controls and determine CHD risk factors for aortic stiffness, and 5) evaluate endothelial function in PCOS cases and controls and changes over five years. CHD risk factors will include: HDLt, LDLc, triglycerides, glucose, insulin, Lp(a), PAI-1, blood pressure, and anthropometric measures. Information will be obtained on medical, reproductive and physical activity history. The investigators state that this study has the potential to identify the determinants of early SCA in this high-risk group of women and has important implications for primary as well as secondary prevention.